Jose Mourinho asked everyone to forget about Alexis Sanchez and focus on Burnley in his pre-match press conference on Friday and his team, thanks to Anthony Martial's second-half goal, just about managed it at Turf Moor.

For the first 45 minutes, barley a thing happened. Ashley Young, back in the United XI after suspension at Luke Shaw's expense, cut inside from left-back to fizz a shot past the far post but that was the sum of the best chances.

Paul Pogba did his best to drive everyone else forward but it was a day of frustration for the French midfielder and it seemed as though everyone associated with United was killing time before their new boy arrived.

The opening period made it easy to see why Mourinho is so keen to bring Sanchez to Old Trafford but then, just as it looked like United might have frozen in the wintery weather, 10 minutes after the break they suddenly woke up.

Romelu Lukaku did well to win possession in midfield, before ignoring Jesse Lingard's run to sweep the ball out to Martial on the left. It was the first time Burnley had looked disorganised and Martial make the most of his chance, crashing a shot in off the underside of the crossbar.

It was United's first shot on target -- and the goal was not particularly deserved -- but the travelling fans behind the goal didn't care. However, thereafter United started to look ragged, as they often have after scoring this season.

There were more nervous moments than out-right chances in truth, but enough to get Mourinho out of his seat and shaking his head. Johann Berg Gudmundsson came closest to equalising when he hit the bar with a free kick.

Martial might have wrapped things up but Nick Pope made a good save at his near post and, in the end, United hung on to record their fourth straight win and fifth straight clean sheet in all competitions.

Still, Sanchez cannot arrive soon enough.

Anthony Martial's ninth Premier League goal of the season gave Manchester United a narrow victory.

2. Martial benefits from Mourinho's tough love

This is the Anthony Martial that Mourinho wanted all along. This time last season, the French forward was being left out of matchday squads and facing up to criticism from his manager. Whatever his manager has done, it seems to have worked.

Martial will have better games for United, but this was still one of those afternoons that shows how far he has come. In freezing conditions, he stuck to his task going forward, stretching the game and attacking his full-back, Phil Bardsley. More importantly for Mourinho, he worked hard going the other way, too.

And when his chance came, Martial took it. There was still a lot to when he received the ball from Lukaku, but he had the composure to take a touch and crash his finish past Pope. Still only 22, he is one of United's best finishers and this was his 11th goal in all competitions this term; he only managed eight last season.

Sources have told ESPN FC that, rather than Henrikh Mkhitaryan, Arsenal initially wanted Martial as part of the Sanchez deal. It is easy to see why. It is also easy to see why Mourinho said no.

3. Crucial weeks ahead for Burnley

Burnley's start to the season led to talk of a European place, but Sean Dyche will have always had his eye on 40 points and, having lost four consecutive games to start a calendar year for the first time since 1987, his side have reached a crucial point.

Even after eight games without a win in all competitions, Burnley are still seventh. The question is, though, what happens from here? Do they pick up enough points to finish in the Top 10? Or will the winless run drag on and see them sucked back toward the bottom?

Dyche won't have long to find out; after a trip to Newcastle and a visit from Manchester City, Burnley have games against Swansea, Southampton, Everton and West Ham. It is the type of run they have to take advantage of, if they want to finish in the top half.

The positive is that, while United at home is perhaps not the type of game from which Dyche, who was managing his 100th game in the Premier League, will have expected to get much, there was enough in Burnley's display to make him feel this disappointing run will end sooner rather than later

Rob is ESPN FC's Manchester United correspondent. Follow him on Twitter @RobDawsonESPN.